COOLANT SYSTEM FOR REDUCTANT TANK

- Caterpillar Inc.

A coolant system for a reductant tank is disclosed. The coolant system includes a valve configured to control a coolant flow to the reductant tank. The coolant system also includes a cyclonic filter element provided in fluid communication with the valve. The cyclonic filter is positioned upstream of the valve with respect to the coolant flow. The cyclonic filter is configured to separate particulate contaminants from the coolant flow to create a filtered coolant flow. The cyclonic filter is also configured to direct the separated particulate contaminants away from the valve. The cyclonic filter is further configured to provide the filtered coolant flow to the valve.

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Description
TECHNICAL FIELD

The present disclosure relates to a coolant system, and more particularly the coolant system for a reductant tank.

BACKGROUND

An aftertreatment system is associated with an engine system. The aftertreatment system is configured to treat and reduce NOx and/or other compounds of the emissions present in an exhaust gas flow, prior to the exhaust gas flow exiting into the atmosphere. In order to reduce NOx, the aftertreatment system may include a Selective Catalytic Reduction (SCR) module and a reductant delivery module.

The reductant delivery module may include a tank for storing a reductant, a pump, and reductant delivery lines. An engine coolant system may be provided in a heat exchanging relationship with the reductant tank for the purpose of warming or thawing the reductant tank. A valve located upstream of the reductant tank with respect to the coolant flow may be configured to regulate a quantity of the coolant entering into the reductant tank or reductant pump.

U.S. Pat. No. 8,082,951 discloses a valve and a method of providing debris resistance in the valve. The valve can include a valve housing defining a valve chamber and at least an inlet port and an outlet port. The valve can include a flow channel extending into the valve chamber and pivotally coupled relative to the valve housing about a pivot axis defined through the valve chamber. The flow channel can include a main portion extending into the valve chamber and a plunger portion disposed outside of the valve chamber. The main portion can have a wall radially spaced apart from the pivot axis. The flow channel can include a rib extending radially inwardly from the wall toward the pivot axis. The valve can also include at least one wing member positioned within the inlet port and secured relative to the valve housing.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a coolant system for a reductant tank is disclosed. The coolant system includes a valve configured to control a coolant flow to the reductant tank. The coolant system also includes a cyclonic filter element provided in fluid communication with the valve. The cyclonic filter is positioned upstream of the valve with respect to the coolant flow. The cyclonic filter is configured to separate particulate contaminants from the coolant flow to create a filtered coolant flow. The cyclonic filter is also configured to direct the separated particulate contaminants away from the valve. The cyclonic filter is further configured to provide the filtered coolant flow to the valve.

In another aspect of the present disclosure, an engine having an aftertreatment system is disclosed. The aftertreatment system includes a reductant tank. The aftertreatment system also includes a pump coupled to the reductant tank. The aftertreatment system further includes a coolant system for the reductant tank. The coolant system includes a valve configured to control a coolant flow to the reductant tank. The coolant system also includes a filter element provided in fluid communication with the valve. The filter element is positioned upstream of the valve with respect to the coolant flow. The filter element is configured to separate particulate contaminants from the coolant flow to create a filtered coolant flow. The filter element is also configured to direct the separated particulate contaminants away from the valve. The filter element is further configured to provide the filtered coolant flow to the valve.

In yet another aspect of the present disclosure, a method for controlling a temperature of reductant tank is disclosed. The method includes introducing a coolant flow into a filter element. The method also includes separating particulate contaminants from the coolant flow. The method further includes creating a filtered coolant flow. The method includes providing the filtered coolant flow to a valve. The method further includes passing the filtered coolant flow towards the reductant tank based on a position of the valve.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an engine system including an engine and an aftertreatment system, according to one embodiment of the present disclosure;

FIG. 2 is a perspective view of a reductant tank and a coolant system associated with the reductant tank;

FIG. 3 is a schematic diagram of a valve and a filter element associated with the aftertreatment system, according to one embodiment of the present disclosure; and

FIG. 4 is a flowchart for a method of controlling a temperature of the reductant tank.

DETAILED DESCRIPTION

Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Generally, corresponding or similar reference numbers will be used, when possible, to refer to the same or corresponding parts.

Referring to FIG. 1, a block diagram of an exemplary engine system 100 is illustrated. The engine system 100 includes an engine 102. In one embodiment, the engine 102 may include any internal combustion engine known in the art including, but not limited to, a diesel-fueled engine, a gasoline-fueled engine, a natural gas-fueled engine or a combination thereof. The engine 102 may include other components such as a fuel system, an intake system, a drivetrain including a transmission system and so on. The engine 102 may be used to provide power to any machine including, but not limited to, an on-highway truck, an off-highway truck, an earth moving machine and other similar machines.

The engine system 100 also includes an exhaust aftertreatment system 104. The aftertreatment system 104 is fluidly connected to an exhaust manifold 106 of the engine 102. The aftertreatment system 104 is configured to treat an exhaust gas flow exiting the exhaust manifold 106 of the engine 102. The exhaust gas flow contains emission compounds that may include Nitrogen Oxides (NOx), unburned hydrocarbons, particulate matter and/or other compounds. The aftertreatment system 104 is configured to treat and reduce NOx and/or other compounds of the emissions prior to the exhaust gas flow exiting the engine system 100.

The aftertreatment system 104 includes a reductant delivery module 108. The reductant delivery module 108 is configured to inject a reductant in the exhaust gas flow. The reductant may be a fluid such as a Diesel Exhaust Fluid (DEF), including urea. Alternatively, the reductant may include ammonia or any other reducing agent. A direction of flow of the reductant within the aftertreatment system 104 is represented by arrows 109.

The reductant delivery module 108 includes a reductant tank 110, a pump 112 and a reductant injector 114, and will be explained in detail in connection with FIG. 2. The aftertreatment system 104 may further include a Selective Catalytic Reduction (SCR) module 116 provided downstream of the reductant delivery module 108 with respect to the reductant flow 109 in the aftertreatment system 104. The SCR module 116 is configured to reduce a concentration of NOx present in the exhaust gas flow.

The aftertreatment system 104 disclosed herein is exemplary. A person of ordinary skill in the art will appreciate that the aftertreatment system 104 may additionally include other components. For example, in one embodiment, the aftertreatment system 104 may also include a mixing chamber (not shown) fluidly connected to the exhaust manifold 106, and the SCR module 116. The mixing chamber is configured to mix the exhaust gas flow received from the exhaust manifold 106 and the reductant received from the reductant tank 110 upstream of the SCR module 116. The aforementioned variations in position and the components included in the aftertreatment system 104 are possible without deviating from the scope of the disclosure and various other configurations not disclosed herein are also possible within the scope of this disclosure.

FIG. 2 illustrates a perspective view of the reductant tank 110. The reductant tank 110 may be a DEF tank. The reductant tank 110 is configured to store the reductant therein. The reductant tank 110 is fluidly connected to the SCR module 116 through the pump 112 and the reductant injector 114 in order to provide a supply of the reductant into the exhaust gas flow. Parameters related to the reductant tank 110 such as size, shape, location, and material used may vary as function system design and requirements.

Referring to FIGS. 1 and 2, the pump 112 is provided in fluid communication with the reductant tank 110. The pump 112 is configured to pressurize and selectively deliver the reductant from the reductant tank 110. The reductant is then introduced within the SCR module 116 by the reductant injector 114 (see FIG. 1) installed downstream of the pump 112. The pump 112 may receive the reductant from the reductant tank 110 through a reductant inlet line 118. An excess amount of the reductant pumped into the reductant injector 114 by the pump 112 may be recirculated to the reductant tank 110 via a reductant return line 120. The pump 112 may include any pump known in the art including, but not limited to, a piston pump and a centrifugal pump.

It should be noted that the reductant is susceptible to freezing. Freezing of the reductant may affect a performance of the aftertreatment system 104. Accordingly, a coolant system 122 is provided within the aftertreatment system 104. The coolant system 122 is configured to heat the reductant thereby increasing its temperature. More particularly, the coolant system 122 is configured to thaw the reductant within the reductant tank 110. The coolant system 122 is also configured to thaw the reductant flowing through the pump 112.

A coolant may flow through the coolant system 122. A direction of flow of the coolant within the aftertreatment system 104 is represented by arrows 123 in FIG. 1. The coolant may be any engine coolant that is configured to cool the engine 102. The coolant flowing through the coolant system 122 is generally at a temperature which is higher than that of the reductant, due to heat transfer between the coolant and various engine parts. In the illustrated embodiment, the coolant is free to flow throughout the coolant system 122 (see FIG. 1). A coolant pump (not shown) may be provided in fluid communication with the coolant system 122. The coolant pump is configured to pump and deliver the coolant from the coolant system 122 to other components of the aftertreatment system 104.

A valve 124 is provided in fluid communication with the coolant system 122. The valve 124 is configured to control the coolant flow towards the reductant tank 110. The valve 124 may embody any type of a conventional valve that allows a flow of fluid therethrough, based upon an actuation command received by the valve 124. In one example, the valve 124 may be a ball valve. Alternatively, the valve 124 may be any other type of valve known to a person of ordinary skill in the art. Further, the valve 124 may be actuated hydraulically or pneumatically. In one embodiment, the valve 124 may be operated by a control module (not shown) for opening or closing the valve 124 and in turn controlling the coolant flow towards the reductant tank 110. In one example, the control module may receive signals from a plurality of sensors in the aftertreatment system 104. In the current example, the sensors may be configured to determine a temperature of the reductant present in the reductant tank 110. When the temperature of the reductant is lower than a certain threshold temperature, the control module may actuate the valve 124 associated with the reductant tank 110.

The coolant may sometimes include particulate contaminants therein. These particulate contaminants may come from elsewhere in the coolant system 122, e.g., they may be small flecks of metallic or non-metallic debris that become entrained in the coolant flow somewhere in the coolant system 122. The particulate contaminants may tend to block or clog the valve 124 provided in association with the reductant tank 110. This blockage of the valve 124 may have an effect on a quantity of the coolant entering into the reductant tank 110. In addition, these particulate contaminants may damage the other various components of the reductant delivery module 108.

The present disclosure provides a filter element 126 in fluid communication with the valve 124. The filter element 126 is positioned upstream of the valve 124 with respect to the coolant flow. Further, an upstream side of the filter element 126 may be fluidly connected to a radiator (not shown) of the engine system 100. The filter element 126 is configured to separate particulate contaminates from the coolant flow to form a filtered coolant flow. A direction of flow of the filtered coolant is represented by arrows 127 (see FIG. 1). The filter element 126 may embody any type of filter known to a person of ordinary skill in the art.

FIG. 3 is a schematic diagram of the filter element 126 and the valve 124. In the illustrated embodiment, the filter element 126 is embodied as a cyclonic filter. The filter element 126 includes a coolant inlet end and a coolant outlet end. The coolant inlet end is configured to receive the coolant that may include debris and/or particulate contaminants entrained therein. Further, the coolant outlet end of the filter element 126 is fluidly connected to an inlet of the valve 124.

When the valve 124 is actuated the coolant pumped by the coolant pump flows through the filter element 126. The filter element 126 separates the particulate contaminants present in the coolant flow from the coolant. In the exemplary embodiment wherein the filter element 126 is a cyclonic filter element, the separated particulate contaminants are directed away from the valve 124 through a lower portion 128 of the filter element 126.

The shape of the filter element 126 is such that the coolant introduced into the filter element 126 may adopt a helical path down through a cylindrical body of the filter element 126. Further, the lower portion 128 of the filter element 126 has a conical configuration. As the coolant flows towards the lower portion 128 of the filter element 126, the particulate contaminants are separated from the coolant flow. The separated particulate contaminants exit the filter element 126 through a port provided within the lower portion 128 of the filter element 126. The filtered coolant flow, that is the coolant flow from which the particulate contaminants and other debris are separated, is redirected from the lower portion 128 of the filter element 126. The filtered coolant flow is directed upwards within the filter element 126, and further exits the filter element 126 through an outlet provided at an upper portion of the filter element 126. In one embodiment, a contaminant reservoir 130 is provided in fluid communication with the filter element 126. The contaminant reservoir 130 is configured to collect the particulate contaminants separated from the coolant flow. The coolant flow from which the particulate contaminants are separated may then flow towards the valve 124.

In an alternate embodiment, the filter element 126 may embody a mesh screen. Apertures present on the mesh screen may be sized such that the larger particulate contaminants are prevented from flowing towards the valve 124. In such an alternative embodiment, a quick release fitting or other means for easily accessing the mesh screen for cleaning may be implemented.

The reductant tank 110 includes a heat exchanger 136 provided therein. The heat exchanger 136 is provided in fluid communication with the valve 124. Based on the actuation of the valve 124, the coolant is introduced within the heat exchanger 136 through a coolant inlet line 132. The coolant is configured to exchange heat with the reductant present within the reductant tank 110 via the heat exchanger 136, thereby increasing the temperature of the reductant. Further, after passing through the heat exchanger 136 the filtered coolant flows out of the reductant tank 110 through a coolant outlet line 134. In one embodiment, the filtered coolant flow may be configured to flow towards other components of the aftertreatment system 104. For example, the filtered coolant flow may be configured to flow into the pump 112.

INDUSTRIAL APPLICABILITY

As described above, the coolant flowing towards the reductant tank 110 may contain debris or particulate contaminants therein. Unless otherwise prevented from contacting the valve 124, this debris may choke the valve 124 of the coolant system 122 and prevent an operation thereof. The choking of the valve 124 may affect the quantity of the coolant flowing towards the reductant tank 110. This may increase a reductant thawing time and may in turn affect an overall performance of the aftertreatment system 104. Further, the valve 124 may need to be replaced in a situation wherein irreparable damage is caused within the valve 124 by the debris.

The present disclosure relates to the filter element 126 provided in the coolant system 122. In the illustrated embodiment, the filter element 126 is shown as the cyclonic filter element. The filter element 126 is provided upstream of the valve 124. The filter element 126 is configured to separate particulate contaminants from the coolant flow, thereby avoiding the choking of the valve 124. In one embodiment, the particulate contaminants are collected in the contaminant reservoir 130 coupled to the filter element 126. The contaminant reservoir 130 may be cleaned and emptied periodically, during maintenance of the engine system 100. The filter element 126 and the contaminant reservoir 130 instead may be easily cleaned or serviced.

FIG. 4 is a flowchart for a method 400 of controlling a temperature of the reductant tank 110. At step 402, the coolant flow may be introduced into the filter element 126. At step 404, the particulate contaminants are separated from the coolant flow. The separated particulate contaminants are directed away from the valve 124 and are collected in the contaminant reservoir 130. At step 406, the filtered coolant flow is created. At step 408, the filtered coolant flow is provided to the valve 124. At step 410, the filtered coolant flow is passed through the reductant tank 110 based on the position of the valve 124. The frozen reductant present in the reductant tank 110 may be thawed on the passage of the filtered coolant flow therethrough.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

Claims

1. A coolant system for a reductant tank, the coolant system comprising:

a valve configured to control a coolant flow to the reductant tank; and
a cyclonic filter element in fluid communication with the valve and positioned upstream of the valve with respect to the coolant flow, wherein the cyclonic filter element is configured to: separate particulate contaminants from the coolant flow to create a filtered coolant flow; direct the separated particulate contaminants away from the valve; and provide the filtered coolant flow to the valve.

2. The coolant system of claim 1 further comprising:

a heat exchanger provided within the reductant tank.

3. The coolant system of claim 1 further comprising:

a contaminant reservoir in fluid communication with the cyclonic filter element, wherein the contaminant reservoir is configured to collect the particulate contaminants separated from the coolant flow.

4. The coolant system of claim 1, wherein the reductant tank is a diesel exhaust fluid tank.

5. An engine having an aftertreatment system, the aftertreatment system comprising:

a reductant tank;
a pump coupled to the reductant tank; and
a coolant system for the reductant tank, the coolant system comprising: a valve configured to control a coolant flow to the reductant tank; and a filter element in fluid communication with the valve and positioned upstream of the valve with respect to the coolant flow, wherein the filter element is configured to: separate particulate contaminants from the coolant flow to create a filtered coolant flow; and provide the filtered coolant flow to the valve.

6. The engine of claim 5, wherein the filter element is a cyclonic filter element.

7. The engine of claim 6 further comprising:

a contaminant reservoir in fluid communication with the cyclonic filter element, wherein the contaminant reservoir is configured to collect the particulate contaminants separated from the coolant flow.

8. The engine of claim 5, wherein the filter element is a mesh screen.

9. The engine of claim 5, wherein the reductant tank is a diesel exhaust fluid tank.

10. The engine of claim 5, wherein the coolant system further comprises a heat exchanger provided within the reductant tank.

11. A method for controlling a temperature of a reductant tank, the method comprising:

introducing a coolant flow into a filter element;
separating particulate contaminants from the coolant flow;
creating a filtered coolant flow;
providing the filtered coolant flow to a valve; and
passing the filtered coolant flow towards the reductant tank based on a position of the valve.

12. The method of claim 11 further comprising:

directing the separated particulate contaminants away from the valve.

13. The method of claim 11 further comprising:

collecting the separated particulate contaminants in a contaminant reservoir.

14. The method of claim 11 further comprising:

thawing of a reductant in the reductant tank based on the passage of the filtered coolant flow therethrough.
Patent History
Publication number: 20150275732
Type: Application
Filed: Mar 28, 2014
Publication Date: Oct 1, 2015
Applicant: Caterpillar Inc. (Peoria, IL)
Inventors: Yong Yi (Dunlap, IL), Jinhui Sun (Dunlap, IL), Arvind Jujare (Peoria, IL)
Application Number: 14/228,752
Classifications
International Classification: F01N 3/20 (20060101);